Chaos and reconnection in relativistic cyclotron motion in an ellipticallypolarized electric field

A theoretical study of the relativistic cyclotron motion occurring in a uni form magnetic field and an oscillating electric field of arbitrary polariza tion is performed, which aims at determining the effect of the ellipticity and the strength of the electric field upon the integrability or nonintegra bility of the system. Unless a circularly polarized electric field is used, the cyclotron system is nonintegrable and displays stochastic behavior in the region where resonance islands overlap. It is found, however, that the stochastic layers become increasingly thin as the polarization angle is mov ed closer coward pi/2 (circular polarization). If the polarization angle is held fixed and the electric field amplitude is increased, the Kolmogorov-A rnold-Moser curve a separating the resonance islands experience a reconnect ion process through which the islands are topologically rearranged. When th e rearrangement is accomplished, the phase space is occupied mostly by regu lar trajectories. [S1063-651X(99)02710-5].